Laser Technology
Lasertechnology
This technology allows translucent materials, such as glass and plastic, to be engraved within their interior area by means of optical laser points. The outer surfaces remain undamaged during the engraving process. The optical laser engraving is contained within the object and consequently, is protected against all outside influences. This technique enables visualization and creation of both two- and three-dimensional designs within the object.
- The technique in detail
Inside the laser diode module a laser beam is generated by a NDYag crystal. This beam is diffracted by light guides into the laser head. Within the laser head several mirrors reflect the beam until it quits the lens as a conical light beam. It penetrates the glass surface and foculizes in the inner glass with due regard to the calculation of the reflaction index. Analytical temperatures up to 20.000 ° C are reached in the process. As a result of the short pulse duration of ca. 3 - 4 nanoseconds combined with a low output power of ca. 1 W a chemical reaction is caused. A caven with the size of only a few my emerges. Radial cracks occur starting from the cavern. These cracks refract the light and create a spot which is visible to the unaided eye.
The reflection of the laser beam by mirrors and the resultant triple-axis mobility of the laser head including the lens allows us to create any 3D structure inside any glass object. We use CAD-files to start the selection. These CAD-files consist of a scatter plot and are generated by a specific software using 3D formats.
- Different laser beams
Red laser beams have a wavelength of 1064 nm, while green laser beams have a wavelength of 532 nm, which means their frequence is doubled. The difference between the types is based on the different sizes of the created spots.
Green laser spots are much smaller than red ones. Thereof green laser beams have a noticeably better resolution and a greater number of spots. The smallest details are only visible using a green laser beam. Certainly the processing time is higher due to the greater number of laser spots. Especially filigran models show the difference in quality.
Our systems operate with green laser beams.
- Velocity
- Laser 1 - the old red laser is decomissioned
- Laser 2 - GREEN - 2 khz (2.000 points per second)
- Laser 3 - GREEN - 2 khz (2.000 points per second)
- Laser 4 - GREEN - 4 khz (4.000 points per second)
The velocity states the maximum number of points, which could be theoretically realized per second. The total processing time can be inferred from it by regarding the travel lengths. Said travel lenghts of the laser head can reduce the effective velocity, depending on the object, to 5 % of the calculated value.
- Maximum Sizes
- glass plates with connected engravings:1980 x 2450 mm,
- with divisible engravings: 1980 x 6000 mm.
- glass blocks: normally our assortment sizes apply
Different glass blocks and flat glasses can be laminated (edges and blank areas could appear possibly).
Please contact us, if you have specific requests about large panes or glass blocks.
- Transition
To engrave larger objects the laser head moves along the x- and y-axis. The engraving is composed by several "scanning fields". The maximum size of a scanning field is ca. 50*50 mm. Larger files are segmented in 20*20 mm scanning fields. The particular laser points are not spherical, because the heigth (z-axis) is larger than the witdth and length. Consequently the points in the center of a scanning field are aligned vertically to the glass surface, whereas the outer points are aligned at an angle (see illustration). The different scanning fields are visible as a grid, when the object is too large. This effect is mostly avoidable in case of 2D-files, for example pictures or flat logos, through mixing the scanning fields (transition).